A timely topic for a safety meeting is about working in excessive heat and humidity. The reason being is workers need to take special precautions because such weather conditions can result in a variety of adverse health effects, from discomfort to serious illness, and even death.

The body reacts to heat by increasing the blood flow to the skin’s surface and by sweating. This results in cooling as sweat evaporates from the body’s surface and heat is carried to the surface of the body from within by the increased blood flow. Heat also can be lost by radiation and convection from the body’s surface.

Under conditions of high humidity, the evaporation of sweat from the skin is decreased and the body’s efforts to maintain an acceptable body temperature could be significantly impaired.

These conditions adversely affect an individual’s ability to work in a hot environment.

With so much blood going to the external surface of the body, relatively less goes to the active muscles, the brain and other internal organs, according to the Centers for Disease Control and Prevention (CDC). This lowers an individual’s mental alertness and physical performance sooner than it would otherwise.

Increased body temperature and physical discomfort promote irritability, anger and other emotional states, which sometimes cause workers to overlook safety procedures or to divert attention from potentially dangerous tasks, the CDC says. What’s more, heat tends to promote accidents due to the slipperiness of sweaty palms and dizziness.

Workers who are exposed to extreme heat or work in hot environments, such as unloading trailers, could be at risk of heat stress. Heat stress occurs when the body’s means of controlling its internal temperature start to fail.

Heat stress can result in a variety of heat illnesses, including heat stroke, heat exhaustion, heat cramps, heat rashes and fainting.

Heat Stroke — This is the most serious heat-related disorder. It occurs when the body becomes unable to control its temperature and sweating becomes inadequate, so the body is unable to cool down.

When heat stroke occurs, the body temperature can rise to 106 degrees Fahrenheit or higher within 10 to 15 minutes. Heat stroke can cause death or permanent disability if emergency treatment is not given.

The symptoms of heat stroke include: hot, dry skin or profuse sweating; hallucinations; chills; throbbing headache; high body temperature; confusion; dizziness and slurred speech. 

To treat a worker with heat stroke, the CDC recommends to call emergency services, move the worker to a cool shaded area, and to cool the worker using methods such as soaking their clothes with water; spraying, sponging or showering them with water; and fanning their body.

Heat Exhaustion — This is the body’s response to an excessive loss of water and salt, which is usually due to excessive sweating.

Symptoms include: heavy sweating; extreme weakness or fatigue; dizziness; confusion; nausea; clammy, moist skin; pale or flushed complexion; muscle cramps; slightly elevated body temperature; and fast and shallow breathing.

The CDC says workers suffering from heat exhaustion should be treated using the following steps: Rest in a cool, shaded or air-conditioned area, drink plenty of water or other cool, non-alcohol beverages and take a cool shower, bath or sponge bath.

Heat Cramps — These usually affect workers who sweat a lot during strenuous activity. This heavy sweating depletes the body’s salt and moisture levels and low salt levels in muscles that cause painful cramps. Heat cramps also can be a symptom of heat exhaustion.

Symptoms of heat cramps are muscle pain or spasms usually in the abdomen, arms or legs. The CDC recommends that workers with heat cramps stop all activity and sit in a cool place a drink clear juice or a sports beverage. In addition, the organization advises that workers do not return to strenuous work for a few hours after the cramps subside because further exertion could lead to heat exhaustion or heat stroke. The affected person also should seek medical attention if any of the following apply: the worker has heart problems, the worker is on a low-sodium diet or the cramps do not subside within one hour.

Heat Rash — This is a skin irritation caused by excessive sweating during hot, humid weather. Heat rash looks like a red cluster of pimples or small blisters. It is more likely to occur on the neck and upper chest, in the groin, under the breasts and in elbow creases.

The CDC recommends that workers experiencing heat rash should do the following: try to work in a cooler, less humid environment when possible; keep the affected area dry and use dusting powder to increase comfort.

Heat Syncope — This is a fainting (syncope) episode or dizziness that usually occurs with prolonged standing or sudden rising from a sitting or lying position. Factors that can contribute to heat syncope include dehydration and lack of acclimatization. Symptoms of heat syncope include light-headedness, dizziness and fainting.

The CDC says workers with heat syncope should sit or lie down in a cool place when they begin to feel symptoms and slowly drink water, clear juice or a sports beverage.

A key to preventing excessive heat stress is educating your workers to the hazards of working in heat. Make sure they understand what heat stress is, the factors that can lead to it and how to reduce the risk of it occurring. BI